The United States have the highest annual incidence rates of breast cancer in the word. It is the second-most common cancer (after skin cancer) and the second-most common cause of cancer death (after lung cancer). . It is estimated that, in 2014, there will be an estimated 1,665,540 new cancer cases diagnosed and 585,720 cancer deaths in the US. Worldwide more than one million new cases of breast cancer are found every year. Apparently, an effective or accurate, minimally invasive, and low-cost solution for breast cancer treatment will have enormous clinic impact and significance on saving women's lives. To address the problems and technical challenges facing breast radiation therapy (RT), together with its collaborator, we proposes a radically different methodology called 4D SGRT technology to dynamically compute on-treatment breast anatomy structure and adaptively re-plan the radiation therapy. The proposed technology uses a non-invasive and adaptive image guidance based methodology. It eliminates uncertainties due to setup, mobility, and deformation for optimized delivery. It is also expected to shortened breast RT session with improved accuracy, and reduces minimum treatment setup time. Successful completion of the project will provide foundation for the next generation breast RT, and make it possible for millions of breast cancer patients to benefit from the most recent technological advances in a timely fashion. The radiation therapy market is growing rapidly with annual cancer rates worldwide projected to increase by fifty percent by 2020, mainly due to aging population, increasing number of smokers and unhealthy life styles. The Fredonia Group estimated that U.S. has $16.8 billion US market for cancer therapies, and it is growing ten percent annually. With over 2,000 radiation treatment machines in the US and many more in the world, the market for a clinically acceptable 3D camera enabled adaptive therapy system is significant.